U.S. patent application number 10/115604 was filed with the patent office on 2003-09-11 for golf shaft and golf club having the same.
Invention is credited to Unosawa, Akira.
Application Number | 20030171159 10/115604 |
Document ID | / |
Family ID | 28671303 |
Filed Date | 2003-09-11 |
United States Patent
Application |
20030171159 |
Kind Code |
A1 |
Unosawa, Akira |
September 11, 2003 |
Golf shaft and golf club having the same
Abstract
It is a subject of the invention to show excellent decorative
properties of golf shafts, to maintain the decorative properties
for a long time, and to improve its usability. An upper ply being
transparent or at least having translucency to the extent that the
interior surface is visible and a lower ply having different
surface configuration from the upper ply and the surface
configuration of which can be seen through the upper ply provided
underneath the upper ply are provided. The lower ply and the upper
ply are formed of materials having different oscillation damping
rate.
Inventors: |
Unosawa, Akira;
(Saitama-ken, JP) |
Correspondence
Address: |
DARBY & DARBY P.C.
805 Third Avenue
New York
NY
10022
US
|
Family ID: |
28671303 |
Appl. No.: |
10/115604 |
Filed: |
April 2, 2002 |
Current U.S.
Class: |
473/319 |
Current CPC
Class: |
A63B 53/10 20130101;
A63B 60/06 20151001; A63B 60/08 20151001; A63B 2209/02 20130101;
A63B 60/10 20151001; A63B 53/12 20130101; A63B 60/54 20151001; A63B
60/002 20200801 |
Class at
Publication: |
473/319 |
International
Class: |
A63B 053/10 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 11, 2002 |
JP |
2002-065691 |
Claims
What is claimed is:
1. A golf shaft comprising an upper ply being transparent or at
least having translucency to the extent that the interior surface
is visible and a lower ply provided underneath the upper ply so
that the surface configuration can be seen through the upper
ply.
2. A golf shaft comprising an upper ply being transparent or at
least having translucency to the extent that the interior surface
is visible and a lower ply having a surface pattern being different
from that of the upper ply provided underneath the upper ply so
that the surface pattern can be seen through the upper ply.
3. A golf shaft comprising an upper ply being transparent or at
least having translucency to the extent that the interior surface
is visible and a lower ply having a surface pattern being different
from that of the upper ply provided underneath the upper ply so
that the surface pattern can be seen through the upper ply,
characterized in that the upper ply and the lower ply are formed of
materials having the different vibration characteristics from each
other.
4. A golf shaft according to claim 1, characterized in that the
surface configuration of the lower ply is a substantially
three-dimensional configuration.
5. A golf shaft according to claim 2, characterized in that the
surface configuration of the lower ply is a substantially
three-dimensional configuration.
6. A golf shaft according to claim 3, characterized in that the
surface configuration of the lower ply is a substantially
three-dimensional configuration.
7. A golf shaft according to claim 1, characterized in that the
upper ply includes a colorless transparent ply or a colored
transparent ply on the surface thereof.
8. A golf shaft according to claim 2, characterized in that the
upper ply includes a colorless transparent ply or a colored
transparent ply on the surface thereof.
9. A golf shaft according to claim 3, characterized in that the
upper ply includes a colorless transparent ply or a colored
transparent ply on the surface thereof.
10. A golf club comprising a golf shaft according to claim 1.
11. A golf club comprising a golf shaft according to claim 2.
12. A golf club comprising a golf shaft according to claim 3.
13. A golf club comprising a golf shaft according to claim 4.
14. A golf club comprising a golf shaft according to claim 5.
15. A golf club comprising a golf shaft according to claim 6.
16. A golf club comprising a golf shaft according to claim 7.
17. A golf club comprising a golf shaft according to claim 8.
18. A golf club comprising a golf shaft according to claim 9.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a golf shaft and a golf
club.
[0003] 2. Description of the Related Art
[0004] Existing mainstream golf club shafts include a carbon shaft
and a steel shaft, and the users make a choice depending on their
own physical capacities or characteristics and performances of
material.
[0005] In recent years, the users tend to attach importance to
decorative properties in addition to performances or
characteristics when choosing a golf club.
[0006] Heretofore, those shafts had plain color, that is, the
carbon shaft was black which was a self-color of carbon fiber, and
the steel shaft was silver (metallic) obtained by plating process.
However, in recent years, golf shafts decorated with various colors
or patterns on the surfaces thereof by paint application or by
metal coating process are increasing.
[0007] However, in the case of decorations on the surfaces of
shafts by paint application or by metal coating process described
above, when they are scratched or peeled off, they are not
functional any more from an decorative point of view, and designs
are limited anyway because they are two-dimensional
decorations.
[0008] For example, the armature golfers tend to choose the steel
shaft that is used by so called leading professional golf
players.
[0009] However, since the steel shaft is heavy in comparison with
the carbon shaft, and thus the armature golfers cannot handle
skillfully in many cases, they use a carbon shaft that looks like a
steel shaft by being painted or by being metal coated. However, as
described above, the base metal may be exposed due to scratches or
peeling, and thus decorative effect to make it look as a steel
shaft may be lost.
[0010] Differences of the characteristics between carbon shafts and
steel shafts include, for example, a difference of oscillation
damping rate.
[0011] In general, since oscillation damping rate of carbon shafts
is high, the impact exerted at the time of meeting the ball is
suppressed by bending of the shaft. However, there is a case where
the shaft which is bent during the downswing cannot be maintained
in its bent state and is restored to the original state during the
course of downswing before the impact, whereby the golfer cannot
take advantage of the head speed.
[0012] In contrast to it, since oscillation damping rate of the
steel shat is low, the impact exerted at the time of meeting the
ball is significant, and thus it might put a heavier physical
burden to the golfer. However, bending of the shaft during
downswing can be maintained and thus the golfer can take sufficient
advantage of the head speed at the impact.
[0013] In other words, the carbon shaft and the steel shaft have
completely opposite advantages and disadvantages with each other
due to the difference of characteristics as described above.
Professional golfers or skilled armature golfers can make use of
advantages of these two types of shafts and make full use of their
performances, while general armature golfers can hardly make use of
their advantages, but may show up their disadvantages in many
cases.
SUMMARY OF THE INVENTION
[0014] Accordingly, it is a subject of the invention to show
excellent decorative properties of golf shafts as well as to
maintain the same for a long time, and thus an object of the
invention is to provide a golf shaft and a golf club in which the
aforementioned subject is solved.
[0015] In addition to the aforementioned subjects, it is another
subject to improve its usability, and thus another object of the
invention is to provide a golf shaft and a golf club in which
another subject is solved.
[0016] In order to achieve the objects, the invention employs the
following technical measures.
[0017] A technical measure of the invention is to provide a golf
shaft comprising an upper ply being transparent or at least having
translucency to the extent that the interior surface is visible and
a lower ply provided underneath the upper ply so that the surface
configuration can be seen through the upper ply. (claim 1)
[0018] Another technical measure of the invention is to provide a
golf shaft comprising an upper ply being transparent or at least
having translucency to the extent that the interior surface is
visible and a lower ply having a surface pattern being different
from that of the upper ply provided underneath the upper ply so
that the surface pattern can be seen through the upper ply. (claim
2)
[0019] In order to achieve another object of the invention, the
invention employs the following technical measure.
[0020] The technical measure is a golf shaft comprising an upper
ply being transparent or at least having translucency to the extent
that the interior surface is visible and a lower ply having a
surface pattern being different from that of the upper ply provided
underneath the upper ply so that the surface pattern can be seen
through the upper ply, characterized in that the upper ply and the
lower ply are formed of materials having the different vibration
characteristics from each other. (claim 3)
[0021] The factors to determine the vibration characteristics of
material include, for example, specific gravity, rigidity,
hardness, and oscillation damping rate.
[0022] Material being transparent or at least having translucency
to the extent that the interior surface is visible includes glass
fiber pre-preg, epoxy resin, phenol resin, thermosetting resin such
as unsaturated polyester.
[0023] The term "transparent" used here means the extent that the
internal surface can be clearly viewed including colorless
transparent and colored transparent, and the term "translucency"
used here means colored state to the extent that at least the
internal surface can be viewed mistily.
[0024] When employing colored transparency, preferably, glass fiber
pre-preg resin or thermosetting resin is colored in advance so that
the entire thickness of the upper ply is colored, thereby
preventing the color of the upper ply from being diminished.
[0025] By providing the lower ply with a substantially solid
configuration which is different from that of the upper ply the
substantially solid configuration can be seen through the upper ply
(claim 4 and claim 6), and decoration having depth and spatial
effect appears on the golf shaft.
[0026] The substantially solid configurations includes, for
example, a rough configuration, a stepped configuration, and a
polygonal configuration. When employing such solid configurations,
the member to be used for the lower ply is formed into the
exemplified configurations, or a separate member is adhered on the
surface of the member to form it into a solid configuration.
[0027] In the case of adhering a separate member, various patterns
including characters, graphics, patterns, and so on can be
employed, and thus freedom of decoration can be expanded very
much.
[0028] Alternatively, two-dimensional decoration such as
characters, graphics, or patterns can also be employed optionally
on the surface of the lower ply having a substantially solid
configuration. With such arrangement, decoration on the lower ply
is protected by the upper ply, and thus decoration on the lower ply
is prevented from being diminished.
[0029] The upper ply includes a colorless transparent ply or a
colored transparent ply on the surface thereof (claim 7 and claim
9), and such transparent ply is preferably a thin coated ply of
transparent coating material applied thereon or of thermosetting
resin, which serves to protect the ply immediately underneath
thereof.
[0030] Preferably, the transparent ply is colorless transparent for
example when the ply immediately underneath thereof is colorless
transparent, colored transparent, or translucent, and is colored
transparent in the same color when the ply immediately underneath
thereof is colored transparent.
[0031] In terms of material having different oscillation damping
rate, when the upper ply is formed of glass fiber pre-preg, or of
thermosetting resin, the lower ply may be of metal material or
carbon fiber pre-preg.
[0032] When metal material is employed, the surface of the metal
material is preferably protected from rust by rustproof plating,
metal film coating, or painting, which prevents the formation of
rust on the lower ply and separation between the upper ply and the
lower ply or deterioration of decorative property due to rust.
[0033] In addition, the surface of the metal material is preferably
processed to increase adhesiveness with respect to thermosetting
resin (including glass fiber pre-preg resin) used in the upper ply,
which may prevent separation between the upper ply and the lower
ply.
[0034] This process includes, for example, surface roughening of
the metal material and plating process or metal evaporation process
by the use of a metal that increases adhesiveness.
[0035] In the case where glass fiber pre-preg is used for the upper
ply, surface roughening is preferably made so that the direction of
roughness of on the rough surface coincides with the direction of
the fiber of glass fiber pre-preg.
[0036] Metal to be used for plating process exemplified here
includes zinc, nickel, aluminum, iron-based or copper-based
metal.
[0037] In the case where carbon fiber is used for the lower ply,
metal evaporation process may be made on the surface thereof in
order to make metal color decoration to make the shaft look like a
steel shaft.
[0038] In the case where the upper ply is formed by winding
multiple layers of ply of glass fiber pre-preg, preferably, fibers
of the pre-preg are laid in the same direction in order to ensure
see-through of the upper ply.
[0039] In this case, preferably, adhesive ply is interposed between
the upper ply and the lower ply at the ends of the shaft on the
head side and on the grip side, which are susceptible to separation
of glass fiber pre-preg, within the ranges that do not impair
decorations on the surface of shaft. This adhesive ply achieves
enhancement of the separation preventing effect of rough surface,
as well as prevention of separation that often happens when cutting
the ends of the shaft during molding of the shaft.
[0040] The adhesive ply used here is preferably thermosetting resin
or glass fiber pre-preg impregnated with the same resin, for
example glass fiber pre-preg impregnated with borax-based modified
epoxy resin (ex. "KS1020/P-162" manufactured by Toho Tenax Co.,
Ltd.).
[0041] When employing this pre-preg for the adhesive ply, it is
formed by laying glass fibers in the bias direction, polymerizing
them in the cross-linked state, and winding around the lower
ply.
[0042] When the upper ply and the lower ply are formed of materials
having different oscillation damping rates, the following effects
are expected.
[0043] Taking a shaft in which the lower pay is made of steel and
the upper ply is made of glass fiber pre-preg as an example, since
the lower ply formed of steel is low in oscillation damping rate
and the upper ply of glass fiber pre-preg has an oscillation
damping rate higher than the lower ply, this shaft has such
characteristics that the lower ply serves to maintain bending of
the shaft generated during the downswing to sufficiently take
advantage of the head speed at the impact, and the upper ply serves
to help the restoring action of the lower ply to accelerate the
restoring speed for absorbing the impact at the time of meeting the
ball, so that the physical burden to the golfer is alleviated.
[0044] Therefore, by employing a golf shaft described in claim 1 to
claim 9 of the invention in a golf club (claim 10 to claim 18), a
golf club which is quite favorable in appearance and in usability
is obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
[0045] FIG. 1 shows a golf club according to the invention; and
[0046] FIG. 2 is an explanatory drawing showing a construction and
a molding method of golf shaft provided in a golf club.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0047] Referring now to the drawings, an embodiment of the present
invention will be descried.
[0048] FIG. 1 shows a golf club 2 provided with a golf shaft 1
according to the invention, in which decoration 11 having depth and
spatial effect can be viewed from the surface of the golf shaft
1.
[0049] The golf club 2 is provided with a golf shaft 1 that can
sufficiently take advantage of the head speed and alleviate the
physical burden to the golfer in addition to decoration described
above.
[0050] The reference numeral 3 designates a head and the numeral 4
designates a grip.
[0051] The construction of the golf shaft 1 provided in the golf
club 2 will be described in detail below.
[0052] The golf shaft 1 comprises a metal shaft 51 constructing the
lower ply 5, pre-pregs 61, 62, 63, 64 constituting an adhesive ply
6, and a glass fiber pre-preg 71 constituting an upper ply 7 as
shown in FIG. 2A.
[0053] The metal shaft 51 is formed into substantially
three-dimensionally by forming the surface into a multistage
configuration, and then applied with a rustproof coating.
[0054] The pre-pregs 61, 62, 63, 64 are glass fiber pre-pregs
impregnated with borax-based modified epoxy resin. The pre-pregs
61, 62 are formed by laying glass fibers respectively in the
opposite bias directions and polymerizing in the cross-linked
state. The pre-pregs 63, 64 are also formed in the same manner.
[0055] The pre-pregs 61, 62 are formed in the same length as the
thinnest portion of the metal shaft 51 including the end on the
side of the head 3, and the pre-pregs 63, 64 are formed in the same
length as the thickest portion of the metal shaft 51 including the
end on the side of the grip 4.
[0056] Glass fiber pre-preg 71 is formed by laying the fibers in
the straight direction, providing the same length as the whole
length of the metal shaft 51, and the width as wide as it can be
wound several turns on the metal shaft 51.
[0057] The golf shaft 1 is molded using the aforementioned members
by the steps of winding the pre-pregs 61, 62 on the thinnest
portion of the metal shaft 51, winding the pre-pregs 63, 64 on the
thickest portion of the metal shaft 51, winding glass fiber
pre-preg 71 on thus prepared metal shaft 51 so as not to produce
any gap therebetween, sintering the same, and cutting (the position
shown by the arrow) into the prescribed length (FIG. 2B).
[0058] The steps formed on the surface is polished into a flat
surface, and transparent paint is applied thereon to finish (FIG.
2C).
[0059] Accordingly, the surface and the three-dimensional
configuration formed on the surface of the metal shaft 51 on the
lower ply 5 can be seen through the upper ply 7, whereby the golf
shaft 1 with decoration 11 having depth and spatial effect is
molded (FIG. 2D).
[0060] When the adhesive ply 6 having aforementioned construction
is employed, the adhesive ply 6 (shown in a satin finished pattern)
appears on the surface of the upper ply 7. Therefore, though a part
of the adhesive ply 6 may be seen through after it is assembled
into the golf club 2, it may be used as a part of the pattern.
[0061] By assembling the head 3 and the grip 4 on the golf shaft 1
thus molded, the golf club 2 shown in FIG. 1 is obtained.
[0062] Though the upper ply is formed of glass fiber pre-preg in
this embodiment, when the upper ply is formed of thermosetting
resin, it can be molded by applying heat and pressure in a die, and
thus polishing process can be omitted.
[0063] When the lower ply is formed of carbon fiber pre-preg
instead of metal, the golf shaft with decorations having depth and
spatial effect can be molded by the steps of winding carbon fiber
pre-preg on the mandrel, adhering a separate member that
constitutes a three-dimensional configuration thereon, winding
glass fiber pre-preg directly on thereon, and then sintering and
polishing the same.
[0064] The method of adhering the separate member with
three-dimensional pattern can be employed for the metal shaft.
[0065] As is described thus far, the invention has the following
advantages.
[0066] According to the invention, since the surface configuration
of the lower ply that differs from that of the upper ply can be
seen through the upper ply, excellent decoration appears on the
surface of the golf shaft, and in addition, the decoration can be
prevented from being diminished.
[0067] Therefore, a golf shaft in which the subjects described
above, that is, to show excellent decorative properties of golf
shafts as well as to maintain the same for a long time are solved
is provided.
[0068] Since the upper ply and the lower ply have different
oscillation damping rates from each other, it can sufficiently take
advantage of the head speed and alleviate the physical burden to
the golfer in addition to the decorative effect.
[0069] Therefore, a golf shaft in which another subject, that is,
to improve the usability in addition to the decorative effect is
solved is provided.
[0070] In addition, since the three-dimensional configuration can
be seen through the upper ply by providing a substantially
three-dimensional configuration on the surface of the lower ply,
excellent decoration having depth and spatial effect appears on the
golf shaft.
[0071] Since the upper ply includes a colorless transparent ply or
a colored transparent ply on its surface, the transparent ply can
protect the ply located immediately underneath the transparent
ply.
[0072] Since the golf club is provided with a golf shaft with
aforementioned excellent effects, it is quite favorable in
decorative properties as well as in usability.
[0073] Having described specific preferred embodiments of the
invention with reference to the accompanying drawings, it will be
appreciated that the present invention is not limited to those
precise embodiments, and that various changes and modifications can
be effected therein by one of ordinary skill in the art without
departing from the scope of the invention as defined by the
appended claims.
* * * * *